Peter Lawrenson

By default, WordPress will load every plugin on every page. The Simple Plugin Selector (SPS) plugin allows the administrator to select which plugins are used on a page-by-page basis. This prevents unneeded plugins and plugin support files from loading. HTTP requests and download size will be reduced, so improving website performance for the visitor.
For example, you probably use your contact form plugin only on your Contact Us page. SPS allows you to deactivate it when the page request is for one of your other pages, so your users don’t download your contact form style sheets and scripts unnecessarily.
The plugin has a user-friendly interface, so the administrator can see easily which plugins are running on each page.
Plugin filtering is disabled in admin context.
Not for newbies! The administrator must have a clear grasp of which plugins are required for each page, otherwise some pages will have errors because a required plugin is not loaded.
<h3>Deactivating</h3>
Deactivating SPS in the normal plugins list will deactivate plugin filtering and remove the SPS file from the mu-plugins directory.
Removing the SPS plugin using FTP will leave an unwanted SPS file in mu-plugins, but plugin filtering will be disabled.
SPS settings are not deleted by plugin deactivation or deletion. Reactivating should pickup filtering where it left off.
<h3>Settings</h3>
Go to Dashboard > Settings > Simple Plugin Selector to set which plugins are required on a page by page basis. If the site has cache or optimize plugins, they should be cleared after changing any SPS settings.
If a new page, post or product is created, all plugins will be activated for that by default until set otherwise in SPS settings.
If a new plugin is activated, it will be loaded for all pages by default until set otherwise in SPS settings.

Simple Plugin Selector

Select which plugins are activated on a page-by-page basis.

asadkn

A simple plugin to assist both theme and plugin developers in MySQL Profiling. Once installed, MySQL statistics will be available at page footer. Visit http://wpsplash.com/mysql-profiler-plugin-for-wordpress/ for more information.

WP MySQL Profiler

Used to profile MySQL queries for performance; with backtrace information for each query (caller functions, lines, file names etc.)

Simple Plugin Selector vs WP MySQL Profiler